The present invention relates to the manufacture of heavy olefins intended for use in particular as the raw materials for making surface-active products, lubricating compositions, and the like. More specifically, it relates to a process for preparing heavy olefins from propylene. This process is particularly suitable for the manufacture of olefins having from 21 to 48 carbon atoms per molecule.
Several processes are known for making propylene oligomers. These processes consist essentially of subjecting propylene to the action of appropriate catalysts. The average molecular weight of the oligomer depends on the nature of the catalyst and the conditions of temperature and pressure at which the reaction takes place. It is known, for instance, that oligomers having an average carbon chain length of 12 can be obtained by causing propylene to react on a catalyst based on phosphoric acid, at a temperature of 100.degree. C. to 250.degree. C. approximately, at a pressure from 20 to 100 atmospheres, and that oligomers having an average carbon chain length of about 24 carbon atoms can be obtained by polymerizing propylene in the presence of boron trifluoride, at temperatures of the order of 10.degree. C. to 50.degree. C., in the liquid phase.
U.S. Pat. No. 3,932,553 describes the oligomerization of propylene in the presence of a boron trifluoride catalyst and a small amount of an olefinic diene to provide oligomers having about 15 to 21 carbon atoms.
U.S. Pat. No. 4,024,203 describes the oligomerization of lower molecular weight mono alpha olefins utilizing a catalyst composition containing a Bronsted acid, a sulfone, and optionally, a Lewis acid, to provide predominantly dimers and trimers.
U.S. Pat. No. 4,041,098 describes a method of oligomerizing straight-chain alpha olefins having from 3 to 14 carbon atoms with a soluble catalyst system consisting of an aluminum alkyl halide and an organo halide.